First look at Microsoft's new 'One Outlook' email client for Windows 11

Outlook Client Hero
Outlook Client Hero (Image credit: Windows Central)

What you need to know

  • Microsoft's "One Outlook" email client inches closer to official unveiling.
  • The app has started working for work and education accounts.
  • Here's a first look!

Microsoft's new web-based Outlook client has been in development for well over a year at this point. In fact, the client itself leaked last year but was inaccessible to people outside the company, that is until now. As of this morning, it appears the app has started working for work and education accounts, meaning we can finally get our first look at Microsoft's new Outlook email client.

The new app is pretty much identical to the Outlook Web experience you can find today by heading to There are a couple of new additions exclusive to this client, such as the ability to configure the ribbon along the top to a more traditional Outlook style. Unfortunately, the app isn't working with personal email accounts just yet, though we suspect support for that will be added once Microsoft officially announced the client.

Source: Windows Central (Image credit: Source: Windows Central)

The only other noticeable differences that we've spotted with the client is that Microsoft has embedded window controls into the Outlook header to make it look more native to the OS. Composing a message or creating an event in the calendar pops up a new window, just like the existing Outlook desktop client.

Windows Central reported in January 2021 that Microsoft was hoping to eventually replace the built-in Mail & Calendar apps on Windows 10 and Windows 11 with this client. It's still too early for that, as the app is marked as "preview" or "beta" in many places. Microsoft also intends to ship this app on macOS and Linux eventually as well. After all, it's pretty much just a web app.

Microsoft hasn't yet announced this new email experience officially, but it's likely to be unveiled soon as the app looks relatively polished. Build 2022 is later this month, so perhaps we'll see an official announcement there.

You can download the app from this link, or you can check out more screenshots of the app below:

Thanks Temmie for spotting this!

Zac Bowden
Senior Editor

Zac Bowden is a Senior Editor at Windows Central. Bringing you exclusive coverage into the world of Windows on PCs, tablets, phones, and more. Also an avid collector of rare Microsoft prototype devices! Keep in touch on Twitter: @zacbowden.

  • Outlook for macOS is simply the best Outlook experiente I've ever seen. 100% native, polished, functional and beautiful. I was hoping for something like that in Windows 11, but it seems that won't be the case. If they replace the (marvelous) macOS client with this web app, I will be very disappointed.
  • If you're talking about the desktop version, that's not going away. This is just the built in basic email/calendar for windows PCs. Windows PCs also still have a desktop app version just as macOS does.
  • I work pretty closely with MS and some of their product folks and the vision is for this to at some point replace the fat client as well.It is still missing a lot though. I was able to see a much more functional internal dog food version a few weeks ago. The person that showed it to me is using it as their only mail client.
  • over 2 years of leaks and... PWA app
  • I know right. It is better than The Web App but not by much. I guess it's still in beta though. We always knew it was going to be based on the PWA.
  • This is disappointing. The current mail and calendar apps on Windows 10 work incredibly well for Gmail. Switching to an PWA would be a huge downgrade. I sincerely hope Microsoft kills this before it goes out the door
  • Before this is ever released as a replacement for Windows Mail and Calendar, it will definitely support Gmail accounts.
  • Yeah exactly. It's going to have to be quite different than the Outlook Web App which is for Microsoft accounts only.
  • Too bad. After a year or more of working on it, they just got the existing UI working "right." Now we'll go through more and new pains with a new UI?
  • This is disgusting. I can't believe they intend to ship this thing being a dumb PWA and calling it a day. At least update the damn design so it looks on par with the W11 design language.
    Let me guess, you won't be able to open the client when you don't have connection, just like 90% of the other PWA apps.
  • I have seen a concept on reddit (, where a guy redesigns the Mail app and makes it inline with the W11's design language.
  • Yeah, unfortunately it's just a concept
  • Yep, UI Designers are great and pretty sure Microsoft has one. But of course their designs will be just mostly ruined by corporate decisions anyways and simply lack of passion on good design. This new client doesn't even look and feel the current Windows 11 Fluent Design. For sure it is still in beta. But Ms is kinda notorious on releasing new thing that is half baked. I hope at least this works offline so user can at least read and write a new emails even without internet, which current UWP Mail client already does so well. Also integration with Windows Share.
  • "Let me guess," You really are just speculating here. Might be worth understanding the final product before judging it.
  • "Let me guess,"
    Aren't we all doing it?...
  • They haven't. It's not released. Why are you assuming that? All Windows Emails apps support offline use.
  • For now we also assume they will support offline use. But MS tends to have history on breaking features that used to be expected and didn't feature it after a redesign or platform shift. Widgets on Windows 11 don't even work with offline unlike the Live Tiles or old Vista Gadgets do. To Do Widget for example is completely disconnected from the native To Do app, its not even nearly instantaneous to sync between the Widget to the app.
  • tbh, this is 100x better than the Win32 app that comes with MS365
  • The f it's not.
  • Nope, the full-fledged Outlook client is amazing. Normal people don't use it outside of their work email environment, but if you need to do lots of heavy duty email work, it's the best.
  • I use it for my Gmail. It is bloated though let's not be too kind on it but it's a decent email app I enjoy using.
  • I suppose on aesthetics, that's subjective, so you can choose which you like better. But in terms of function, Zac said this is about like the web app, which is missing all of the power functions that make Outlook the best email client on the planet: complex rules (server and client), color-coded categories with ability to assign multiple categories per item, VBA for power handling and automation, archiving features, searching and sorting contacts by category, card and list views for contacts, list view and search for calendar entries, specify From field using distribution groups, and many, many more features. Most of those are not just nice-to-have features for me, but critical requirements. Sure, if you are just a casual emailer, most of those are not needed, hence the value in a simplified UI. I respect that. But make no mistake, this is in no way a replacement for the Win32 Outlook desktop app we have now.
  • @ GraniteStateColin: Don't get ahead of yourself. It's a replacement for the Windows app, not Outlook 365 Win32 Desktop client.
  • I was responding to the comment that this is "100x better" then the desktop Outlook client. Having said that, Zac has said that eventually MS does plan to unify everything into this new version, years down the road.
  • Mind to expand, articulate your opinion?
  • Can you list down what are the things makes this better than Outlook Desktop that comes from M365?
    Saying it launch faster and being lightweight alone doesn't make it 100x better.
  • Really, can it manage multiple Exchange Server accounts at the same time as the Office version does?
  • Meanwhile, Microsoft's dev team made a big deal about announcing MAUI 2 years ago or so, which allows developers to build a single codebase that targets multiple platforms, including Windows desktop, macOS, iOS, Android and Web. And then they go and build their flagship product as a PWA instead of using the very same tools they're pushing to devs. I have no idea why MS is pretending to care about cross-platform dev frameworks when they seem to have already decided internally that they don't care and they're just going to push PWA's for everything new. Meaning that MAUI, which conceptually is a great idea, will never get the attention it deserves, and will remain a substandard framework that will lose developer interest, since devs will clearly see the lack of investment from MS themselves.
  • I agree that Microsoft's inability to require all its teams to eat their own dogfood is a massive cultural problem for the company. Having said that, PWA's can be very capable and provide a high performance front end. Being a PWA isn't necessarily a problem for any given app. To your point, though, it would be nice if MS gave clear and consistent recommendations for Windows development and ensured it led by example.
  • I honestly feel like Microsoft ocmmitted to this PWA direction for Outlook years ago and it appears to be just as disappointing as predicted.
  • After a quick installation and look, it seems to me that serious work is left to be done to make this multi-account capable, which is a must have. Or, have multiple instances. In any case, account switching should not take more than a blink of the eye. It should be able to receive notifications for all accounts in parallel, not dependent on which account is active.
  • For me, it needs to work with multiple accounts active at the same time. Having to switch accounts would be a significant downgrade (but clearly better than not even supporting more than one account). I need the overlay calendars to show all my tenant and personal connections on a single view. Desktop (Win32) Outlook handles this almost perfectly (much better than other Windows apps and much, much better than the Android Outlook app, which allows Work account security that prevents overlaid calendars). I said ALMOST perfectly, because there remain two big opportunities for multi-account improvement with desktop Outlook: 1. Ability to change sender/tenant/calendar from Meeting invites (Outlook supports this perfectly for email, but not for calendar items) 2. Ability to create Teams meetings for more than 1 tenant at a time (this is probably more a Teams limitation than an Outlook one, but it manifests in Outlook Meetings and it's a huge problem)
  • I think the things you're describing are the very reason why there are always two email clients, a built in one and one for more "advanced" users. I also use the desktop app because I need the extra features, but for someone who just needs basic emailing/calendar functionality the web/PWA outlook is completely fine.
  • I think that has been true, but it sounds like MS' long term plan is to unify everything into this new app and stop upgrading the old Desktop app.
  • Although now includes many of the features that keep me using the Outlook for desktop version, there is still one feature that they haven't included, and if they're releasing it for businesses maybe it will be coming. The feature? Oh yea! the ability to set the reminder times to what I want and or need. For example: change 15 minutes to 45 minutes etc. Let's also hope that they get it to Android devices soon too. I already use on my Android phone, but using it as an app would be a better experience.
  • You can already change reminder times for calendar events on both and on the android app
  • Can I drag an email message and release it in a file explorer folder? To me, that's a defining element of whether this interacts with the rest of the OS. Otherwise, it's still just a web browser window.
  • You can not.
  • This ^^ Many seem to forget this feature, and it is such a normal behaviour among native apps. For this to be considered as an "app" regardless even its web-based is to have this feature. Also ability to open email files from a File Explorer and full open this as expected.
  • This isn't just a PWA or web wrapper. It appears to leverage system-level resources for animations and load times. That was my only real annoyance with OWA/ - looks pretty, but everything just takes a half-second too long to react and load compared to something like the Windows Mail and Calendar apps. With this Outlook app preview, it finally feels native, although it's incomplete. (For example, clicking To Do opens a browser window; presumably the final version will be capable of triggering the To Do desktop app.) Whether this will be viable to me depends on if and how they implement multiple email and calendar accounts. If it's bound to a single account, or keeps's incredibly janky implementation of an added Gmail account, forget it. Also, a "use system setting" dark mode would be great...
  • "Composing a message or creating an event in the calendar pops up a new window, just like the existing Outlook desktop client." You mean Outlook Windows client. The Outlook Desktop client doesn't do this.
  • The most embarrassing part isn't that it's more basic than the Win32 app (it doesn't compete against it) but this is what Microsoft consider is equate to compete with the built-in MacOS Mail app. Which is excellent. You have to wonder why MS bother. None of the built-in Windows apps are ever any good. Strangely Window Vista/Windows 7 had great Mail, Calendar, Messaging, Photo Gallery, Movie Maker and MS killed them for the crappy touch focused apps in Windows 8 and we've still got them today. Windows Live Photo Gallery competed with Apple Photos app. As did Windows Live Mail.
  • Sorry, replied to wrong comment.
  • Weird, twice in row, I replied to bradavon's prior comment, but it kept putting it here in Android app on Duo 2. Worked to place it correctly on web site.
  • I posted a comment below and it replied to some one else's.
  • It does for me. Perhaps a different setting or use of terminology? If you hit the new Appointment or New Meeting buttons (or press Ctrl+Shift+A or Ctrl+Shift+Q, respectively), or double-click an empty spot on the calendar, it opens a new window to create the appointment or meeting. Same with the new Message button or Ctrl+Shift+M for a new email message.
  • The 2 big questions though are:
    1 - Will it support offline support? (for both emails, attachments, etc. like the current desktop version can)
    2 - Will it have proper multi-account support? So far it looks good, but I hope they make the UI consistent with Teams + Loop + etc. (e.g. the search bar placement and size, nav elements spacing, etc.) Otherwise it'll be like the old apps again where everything was inconsistent.
  • Hopefully, full offline capability is coming, as of currently it can't. But since this is pre-beta version that was leaked, there is a chance the real beta version may have one. Offline capability needs to be in beta which indicates the maturity of such feature is there (I hate that offline capability is becoming a feature now when it used to be just a natural thing to have on an app). Multi-account support is a must as well, considering the app it will replacing is fully capable of one. Its pretty much expected on any email client app to have multiple account support.
  • So it's basically just the Outlook website, as I expected. What a joke lol
  • It installs quickly. Just a few minor nitpicks. It defaults to an enterprise account with no obvious way to switch to a personal MSA. Another one is that it pulls from the themes in Outlook for web, meaning in my school's org it's either OW MY EYES with an orange accent or OW MY EYES with a deep blue accent.
  • Yep killer feature. Fail MS.
  • Does this have the Sweep function? I wish Outlook had it. The only place I see it available is in a browser. It's hands down my favorite email function for cleaning out my emails.
  • I actually like the regular mail app that windows has. Outlook looks horrible and borderline unreadable on my 4k monitor because it doesn't scale well. Regular mail app is basic but enough for my needs.
  • This looks just like Outlook in our work/school Office/Microsoft 365...almost exactly the same.
  • Why isn't email a tab in Teams? You can do everything else in Teams, so it feels weird having to leave for email. Does Microsoft not use their own software? Also, can they make desktop teams not feel like a mobile app. It is so simplistic, not even being able to switch tabs without losing your work flow. It is sad that the iPhone Teams app works great while on Microsoft's own platform it feels unfinished and lacking.
  • You can't possibly be using an Enterprise version of Teams. Mobile versions are no where near the same functionality.
  • How does this not have touch swipe actions??? What in the world have they been doing for 2 years :(
  • microsoft doing what they do best. take an app and make it into a Horrible web wrap that's complete garbage... and they wonder why Apple keeps selling more and more Macs each quarter.... Apple has a Native email app and it's 10x better than what MS offers
  • I still use Thunderbird, it does what I require, and I see no reason to change from it. Such a shame, there are so few email clients around these days.
    The best one Ms produced for just email was outloook express, it was easy to use and worked well, just produced that with a few updates I am sure it would do well.
  • Ohh I had totally forgotten about Outlook Express. It was great indeed.
  • This is terrible. Not very nice indeed.
  • Why not just update the UI of the current mail app :V
  • You need a work or school account to sign in and use, the app, doesn't work with out one
  • If only the article stated that. Oh look, it does.
  • Is seeing and modifying time zones going to be easier now? The Windows client just doesn't even bother.
  • Will it have end to end encryption? Without this it's useless and prefer to stay with browser based email , more secure.
  • "Disgusting" - as Zac would say :D
    Real Outlook in Office 365 finally looks more modern so I'm switching to it and already admire all that functions. Just list of emails could be bit cleaner, with bigger difference which ones are unread still